Burglar-alarm



I i u: United States granted to me July 17,1888, No.

rrrcn.

vcijIARLns PHnLPs, 'or SALEM, MASSACHUSETTS.

BU RG LAR-ALARM.

SPECIFICATION forming part of Letters ratent No.412,ee1,t1ated october s, 1889.

Application filed January 22. 1889. Serial No. 297,128. (No model.)

Y Salem, in the county of Essex and State of Massachusetts, have invented certain new 'and useful Improvements in Burglar-Alarms, i ofl which the following is a specification.`

This invention hasfor its object to provide y an improved portable burglar-alarm of such construction that when placed in contact with a door .it will' be prevented from operating by such contact till the door is opened,

and when the door is opened the alarm will y be released and allowed to operate.

The invention is an improvement lon alarms of the class shown in Letters Patent of the 386,265; and it consists in the improvements which I will now proceed to describe and claim. l

Of the accompanying drawings, "forming a part of this specification, Figure l represents a perspective view of my improved burglaralarm. Fig. 2 represents a top view of the same, the cover or upper portion of the casing being removed. Figs. 3 and 4 represent top views of the improved alarm in contact with a door.

The same letters and figures of reference represent the same parts in all the accompanying drawings.

. In the drawings, ct represents the casing which contains the alarm mechanism, the

. latter being of any suitable construction, and

preferably having a spring-impelled arbor b,

'provided with a gear c, which meshes with a pinion d on an arbor f, to which is affixed a spur-wheel. This is an ordinary form of alarm mechanism, and of itself constitutes no part of my invention.

My principal improvement consists, first, in truncating or cutting away one side of the casing a, and thereby forming a beveled face 2, and givingv the side of the casing on which Said face is formed an angle 3, and, secondly, providing a lever or detent, which is pivoted within the casing, and has an arm or part, as p, in contact with. the bell-hammer or some other suitable moving part of the alarm, so as to be oscillated kby the operation of the alarm, and another'arui or part, as p', which projects through the beveled face 2 of the casing, and stands within-a line which would be formed by a continuation of the main portion 5 of the sideon which vsaid beveled face is formed, as shown in Fig. 2, in which the dotted line indicates the imaginary extension of the side 5.

lVhen the alarm is set for the operation against the door, the beveled face 2 is placed against a door, as shown in Fig. 3, so that the detent-arm p is in contact with the door, and

,is thereby prevented from oscillating, the

arm p of the detent being thus caused to hold the hammer, and thus prevent the operation of the alarm.

The beveled face 2 is short-er than the side 5, so that when the door is opened the movement given the casing by the door will cause the side 5 to bear against the door, thus removing .the beveled face 2 from contact with the door, the casing turningl on the angle or ful- Crum 3. This change in the relation of the casing to the door frees the detent-arm p from contact with the door, as shown in Fig. 4, and permits the alarm to operate, the detent being free to oscillate, so that it cannot hold the hammer 7c. The object of this improved arrangement is to permit the alarm to operate well back from the outer or swinging edge of the door, so that a burglar cannot reach in and grasp the alarm before it has had time to operate sufficiently. If it were not for the beveled face, a part of the casing would have to be placed in contact with the door-jamb when used with an inwardly-swinging door, as shown on my former patent above referred to, so that the alarm can be grasped when the door is slightly opened. My above-described improvement, however, enables the casing to bear against the door only and at any desired distance from the outer edge.

and preventing the door from being scratched or marked by its rubbing contact with the A casing. I prefer to make the projecting detent-arm p of wood, both for the sake of cheapness and to prevent the scarring or marking ofthe door by contact with said arm.

The hammer la may have an arm s to bear IOS) against a door or a window, snob as shown in my former patent. I prefer to give the bottom of the casing a slope or bevel to aocommodate the difference in height between the door-sill and the Hoor when a portion of the casing has to rest on the sill and a portion on the floor. It' desired, instead of sloping the bottom of the easing, a block or leg may be hinged to the bottom of the casing and arranged to support the outer side ot' the same at the same height that the inner side is supported by the door-sill.

The spring-arbor b is provided with a detachable key i', and the top of the casing has a raised shoulder n, against which the pivoted handle t of the key bears when it is desired to lock the alarm and prevent it from operating.

I claim- I 1. The casing having one side truncated or beveled to form a shorter beveled face 2 at an angle with the main portion 5 of said side, combined with an alarm mechanism Within the casing and adelent pivoted to the easing and having an arm in Contact with a moving part of the alarm and another arm projecting through said beveled face and arranged to vibrate freely Within the space 'between said beveled face and a continuation of the longer portion 5, substantially as and for the purpose specified.

2. The easing having the beveled face formed on one of its sides at an angle to the main portion of said side, and an anti-friotion roller journaled in the casing near said angle, combined with an alarm mechanism within the casing and a detent pivoted to the easing and having an arm in Contact with a moving part of the alarm and another arm projecting through said beveled face and arranged to vibrate freely within the space between said beveled face and a continuation of the longer portion 5, substantially as and for the purpose specified.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this th day of January, A. I). 1889.

CHARLES P l'l E L PS.

\Vitnesses:

C. F. BROWN, W. C, RAMSAY. 

